Rapid and sensitive detection of chemical warfare and biological agents have been an area of growing interest and importance. There are many current approaches toward chemical warfare agent (CWA) detection such as ion mobility spectroscopy (Cottingham, K. Anal. Chern. 10/1103, 435A439A), surface acoustic wave (Williams D.; Pappas G. Field Anal. Chern. Technol. 1999, 3, 45-53), microcantilever (Yang Y; Ji H-F.; Thundat T. J. Arner. Chern. Soc. 2003, 125, 1124-1125) and interferometric devices (Sohn H.; Letant S.; Sailor M. J.; Trogler W. C. J. Arner. Chern. Soc. 2000, 122, 5399-5400). While some of these methods show CWA simulant detection at low concentrations, specificity and discrimination among chemical threat agents is still lacking. Swager (Zhang S-W.; Swager T. M. J. Arner. Chern. Soc. 2003, 125, 3420-3421) has disclosed a novel fluorescent chemical detection method that yielded fluorescent species upon reaction with CWA simulants. However, Swager's chemical sensors do not allow for chemical modification amenable to a broad range of analytical platforms and suffer from low Stokes shifts (65 nm) with significant overlap of exciting light absorption and fluorescent emission. This effect results in low detection sensitivity to CWA simulants. Slow kinetics also limits sensitivity. Furthermore, it is important that the detection method or materials used allow for integration into multiple analytical platforms.
Moreover, long-wavelength fluorogenic chemical sensors that are reactively activated by biological agents do not exist. Fluorescent markers (e.g. green fluorescent protein and derivatives) currently used in cell biology are costly and suffer from background fluorescence from unreacted probes in experiments designed to detect molecular interactions.